Though it’s not open to the public yet, the first riders have taken the plunge on the world’s tallest water slide.

Schlitterbahn’s Verruckt slide in Kansas City had its first human riders this week. The world’s tallest water slide had water park designer Jeff Henry and ride engineer John Schooley taking the first plunge.

The debut of the world’s tallest water slide has been delayed three times.

The ride’s official opening date was initially supposed to be in May. It was moved from May 23 to June 5 for more testing, then was pushed back again to June 29. Problems with the conveyor system that hauls four-person rafts to the top of the 17-story slide forced park officials to cancel two media sneak preview days, and the June 29th public opening. No new opening date has been announced.

Guinness World Records has certified Verruckt as the world’s tallest water slide.